On my way to meet Isaac Kornbluh, who runs the Schomrim neighbourhood patrol (the word means 'guardians’) in the Haredi Jewish enclave in Stamford Hill, I managed to misplace his address and found myself lost.

The Haredi – strictly-Orthodox Jews who trace their ancestry to 18th-century Eastern Euope – are one of the most close-knit, insular and private communities in Britain. More than 20,000 live in Stamford Hill, in north-east London. But it is a community, it seems, in which everybody knows everybody, and where a stranger is noticed.

As I fumbled through my notebook, a woman stopped. 'You look lost,’ she said helpfully. Ah, I wanted Isaac? First left, then right, number 16.

It is a community too in which everybody seems to be in a hurry.

Earlier that afternoon, I had been sitting on Clapton Common, a small park adjacent to a busy main road. Stamford Hill is a cosmopolitan neighbourhood, but even here the Haredi are strikingly conspicuous. Across the park stood a large, Victorian brick building - a centre of learning, perhaps, or a synagogue, and men and boys moved back and forth across the park, all dressed in variations of the traditional Haredi dress - the high-crowned black hats, ringlets and frock-coats.

In the 18th century, the Hasidim - the largest group of Haredi Jews, who comprise perhaps ninety per cent of the Stamford Hill community - were noted for the ecstatic fervour of their worship. 'They conduct themselves like madmen,’ railed a denunciation by the rabbinical authorities of the day, 'and explain their behaviour by saying that in their thoughts they soar in the most far-off worlds. When they pray...they raise such a din that the walls quake.’ But on the streets of Stamford Hill they looked as solemn as undertakers, hurrying purposefully along, their gazes fixed firmly ahead, a world apart from from the idlers outside the betting shop, the hoodies loitering on the green.

Beneath their hats and locks they had a scholar’s pallor. Many, one noticed, wore spectacles. It was once assumed that it was strain brought on by the long hours of study in the yeshive, or Torah schools, that affected the eyesight of so many Haredi men. However, a study in Israel suggested that much of the blame lay with shockelling - the fervent rocking backward and forward motion that students make as they read the texts, and which causes an incessant change of focus in the eyes leading to myopia.

'Let me tell you something,’ said Isaac Kornbluh. He was a short stocky man of 61, grey bearded, curls protruding from his yarmulke. He was dressed in a white shirt, the tzitzit, or ritual tassels - a reminder of God’s commandments - dangling over his black trousers. 'People in this community have lots of children, and they’re always busy. 24 hours a day. They’re going to the synagogue, going to study, to work, to see their family, back to the synagogue, social events in the evening. It’s a very full life.’

Kornbluh is, by his own description 'a fitness fanatic’ who jogs five or six miles each day - not a type, it seems, much found in the Haredi community.

'I try telling my friends, you need to live healthy. They say, “I’ve got no time...”. I maintain, if a person wants something he’ll find the time. I say to them, in the morning after you go to pray, go out for a brisk walk...’ He laughed. '“Got no time....”’

While mainstream Judaism in Britain is in decline, as people 'marry out’ and abandon the faith, the Haredi community is expanding at a phenomenal rate.

A report by the Board of Deputies of British Jews in 2008 estimated the size of Britain’s strictly Orthodox community at close to 30,000 people, around 10 per cent of the nation’s Jewish population. Within the Jewish community at large, the Haredi have traditionally been regarded as , eccentric, inward-looking - some would say religious extremists.

In many ways they are a community frozen in aspic - a repository of life as it was lived in 19th century Eastern Europe, where tradition is held sacrosanct and modernity is largely scorned.

It is a deeply conservative community that venerates religious learning above all else and in which Yiddish is the primary language. Following the Biblical commandment to 'be fruitful and multiply’, families of seven or eight children are common; relations between the sexes are stringently policed, and arranged marriages are the norm. It is a community where a lack of secular education means that economic hardship is rife, and dependence on benefits is high. A community where television, secular newspapers and visits to the cinema are forbidden, where the internet is frowned upon, and where outsiders are treated guardedly.

The word Haredi is a fairly recent coinage, an umbrella term for strictly Orthodox Jewry. It’s literal meaning is 'fearful’ - in this context 'trembling in the face of God’. The Haredi see themselves as defenders of the faith - engaged in struggle which dates back to the rise of the Jewish Reform movement in early 19th century Germany, when liberal thinking started to challenge the traditional religious teachings and practices. Along with that came the increasing assimilation of Jews within mainstream society and a rise in secularism in which religious learning was exchanged for the scholarship of the university. In the face of this drift from tradition, the Haredi regarded themselves as the last redoubt of orthodoxy, taking sustenance from their rigid observance of the halacha - the body of ethical and ritual injunctions governing Jewish life. Even their appearance symbolised a defiant resistance to any trace of modernity. The Holocaust brought the Haredi to the brink of extinction, but also created the conditions that enabled the spread of ultra-orthodoxy, the determination to remake the past - its language, its dress, its rituals and practices - in new soil, in Israel, America and Britain.

There are now estimated to be around 1.3m Haredi worldwide, and according to a 2007 study by Dr Yaakov Wise at the University of Manchester, strictly-orthodox Jewry in Europe is expanding more rapidly than at any time since before the Second World War. In Britain - home to the largest Haredi community in Europe - almost three out of every four Jewish births are in the Haredi community. If current trends continue, the strictly-Orthodox will constitute the majority of British Jews by 2050.

The Haredi community first took root in Britain in Gateshead at the end of the 19th century, when a small group of Jews from Lithuania docked in Newcastle upon Tyne. Appalled at what they regarded as the laxity of the local synagogue, they established their own on the other side of the river.

They built Britain’s first yeshiva (an institution for Torah and Talmudic study), a women’s seminary, and a kollel - a centre of rabbinical studies for married men.

With all of the great centres of Orthodox Jewish scholarship in Europe having been destroyed during the Holocaust, Gateshead became the largest such centre outside the United States and Israel. It remains the principal centre of learning for the Haredi in Britain.

In Stamford Hill, a small Haredi community that had lived in the area since the end of the 19th century was swollen dramatically by the influx of pre-war refugees and survivors of the Holocaust. The population has grown with arrivals from Israel and America. Now within a tight geographical area, little more than a square mile, there are no fewer than 74 synagogues, or shuls, 32 orthodox schools, kosher supermarkets, butchers, fishmongers and a multitude of other businesses.

To the outsider, the Stamford Hill Haredi community may seem like one confusing, amorphous whole, but in fact it is made up of a number of different streams, mostly Hasidic.

Hasidism had its roots in Podolia - what is now Ukraine - in the early 18th century, a populist movement that emphasised an ecstatic form of worship, deeply rooted in mysticism, and that quickly spread throughout Eastern Europe.

The Hasidim are themselves subdivided into numerous rabbinical dynasties - the Satmar (the largest group), the Gerer, the Belzer and the Bobover, all taking their name from the village or town in Poland, Hungary or Ukraine where they originated, and each distinguished by some slight variation of religious practice and of dress.

At the head of each dynasty is the grand rabbi, or Rebbe - nowadays all of whom are to be found living in Hasidic communities in New York or Israel. More than just a religious teacher, the Rebbe is held to be the fount of all wisdom and authority, on domestic, financial and marital matters - the repository of a stream of learning and wisdom that extends back through the rabbinical teachings and commentaries, to the Talmud and the Torah, and thus to Abraham, Moses and God Himself.

Walking around Stamford Hill, it is the geometry of family relationships that you notice. There are groups of mothers uniformly dressed in the mandatory dark coats and long skirts, and wearing the wigs that are an obligation for married women, pushing prams, a handful of children in tow. There are groups of men, but seldom men and women together.

Modesty is paramount to the Haredi, and the mingling of the sexes is strictly regulated. Unmarried boys and girls will have little contact with the opposite sex outside their families. At concerts and wedding parties men and women will always be separated. A Haredi man will avoid making eye-contact with any woman other than his wife, and would never shake hands.

Among the Gerer, the more traditional will observe the rule that even husbands and wives should not be seen walking on the street together, giving rise to the joke: 'Who was that woman I saw you with last night?' 'Not my wife! Not my wife!'

The Torah, the Five Books of Moses that constitute Judaism’s founding texts, and which are held to be the unmediated word of God, contains 613 Mitzvot - or 'dos and don’ts’ - of which one, held among Haredi to be perhaps the most important, is to study Torah.

The act of study is a supreme religious obligation, as much for the layman as the rabbi, and the talmid hakham - the student of the Talmud, the compendious volumes of rabbinical discussions pertaining to Jewish law and custom - is venerated above all others.

All Haredi children in Stamford Hill attend Jewish schools, all of them single-sex, and all but one of them private.

An Ofsted report on faith schools schools in 2010 noted that most of these Haredi schools have few resources, and many are in converted houses. Fees are heavily subsidised by the community at large, but for families with five, six or more children to educate the burden can be crippling.

For boys in particular, education revolves almost entirely around religious studies. The school week can sometimes be more than 40 hours, with the non-religious curriculum taking up only six or seven hours, mostly covering English, mathematics and general knowledge.

In the last round of Ofsted inspections in 2008, more than a third of the strictly Orthodox schools under inspection were criticised for the quality of their secular education.

Schools argue that many aspects of non-religious studies are actually covered in the study of the Talmud ('a place,’ as the writer Jonathan Rosen has described it, 'where everything exists, if only one knows how and where to look’) but the Ofsted report noted that it 'can be difficult even for experts to decipher the curriculum’.

By their mid-teens boys will have entered a yeshiva, where they will remain until their shidduch - an arranged marriage, which usually happens between the ages of 18 and 20. A married man will then go on to a kollel, either full or part-time. In recent years, the enthusiasm for study has become more, not less, intense. Until the 1970s full-time learning in the kollel was unusual - Gateshead was the only one in Britain. But now it is estimated that more than 20 per cent of married men continue their studies in a kollel well into middle-age and beyond, supported by their family. It is not unusual for wives to take on the burden of providing for their families.

This emphasis on religious learning exacts a high price in other ways. Haredim may be well educated in Jewish law, but many are poorly equipped for employment in the outside world. Few boys will have GCSEs, almost none will have A-levels. More than ten per cent of men obtain a rabbinical qualification, but very few have a professional one. Many take jobs in the community that allow time for study.

A 2003 survey suggested that between a quarter and a third of all men work in property; 18 per cent work in retail; 17 per cent teach in local Haredi institutions. The diamond business, centred in Hatton Garden, is a traditional mainstay. Such are the ties to the community that very few will chose to work outside it.

Of the Orthodox Jewish day schools in Stamford Hill, the Yesodey Hatorah Senior Girls School is the only one to have voluntary-aided status.

The school’s principal is Rabbi Abraham Pinter. I met him at his office at the school. He sat behind his desk, wearing a black beaver hat and top coat. His grey beard gathered in clouds around his face, and sharp, amused eyes blinked behind rimless glasses.

Rabbi Pinter is a ubiquitous and much-respected figure in Stamford Hill, a man who seems to enjoy his position as the public face of the Haredi community. He runs three schools, and is an influential voice in any number of bodies and organisations. In 2008 he was listed at number eight in The Times’s Jewish Power List - ahead of Lord Levy and Israel’s envoy to London, Ron Prosor.

A discursive conversationalist, much given to jokes and ruminations, he has a reputation for worldliness - 'he has a Blackberry,' somebody told me.

He is the scion of a distinguished rabbinical dynasty; his brother is the rabbi of his own synagogue in Stamford Hill - not an important one, Rabbi Pinter suggested with disarming candour; compared with others in the community it was only 'Ryman League’.

Yesodey Hatorah was founded in 1942 by Rabbi Pinter’s father as an independent school with separate sections for boys and girls.

The girls' senior department became a voluntary aided school in 2005, and at the same time moved into superb new, purpose-built accommodation. Tony Blair attended its official opening. The school has 260 pupils, from 11 to 16, drawn from all sections of the Haredi community.

When the school became voluntary aided, Rabbi Pinter told me, there had been some parental concern about having to follow certain aspects of the national curriculum.

'For example, the law is that you have to provide sex education. But parents can choose to opt out. 100 per cent of our parents opt out. Sex education is something we deal with on our own terms through the Jewish curriculum, based on very strong family values.’

He twisted a lock of grey hair in his fingers.

'A question I’m asked is, “How many teenage pregnancies do you have in the community?” To which I reply, “Are you talking about inside or outside marriage? Outside marriage, none.”’

I had never seen a school as clean and orderly as Yesodey Hatorah, nor a more well-behaved body of students. The last full Ofsted report on the school provided an embarrassment of superlatives, rating it 'exceptionally and consistently high’ in virtually all categories. 'Attendance is well above national average,' the report noted. 'Behaviour is superb; in a student questionnaire over 90 per cent stated they liked learning, and above all their joy is obvious.'

While the education of boys is centred on religious study, girls enjoy a much more balanced curriculum, at primary and secondary level. In 2009 83 per cent of the pupils at Yesodey Hatorah sitting GCSEs gained five or more A to Cs.

The attitude to learning was what defined a Jew as Haredi, Rabbi Pinter said. 'For the Haredi, higher education would be in Talmud or Jewish learning; in a modern Orthodox person it would be going to university. There is a difference in aspiration. For a modern Orthodox person getting a doctorate might be an aspiration in its own right; a Haredi person would say, “What do you need it for? You could be an authority in halacha [Jewish law] - why would you want a PhD in physics?”

'I’ll show you...’

He rose from his chair and called out for his secretary.

'Mrs Greenhouse!’

A smiling face appeared at the door.

'Mrs Greenhouse, when you’re looking for a son-in-law what are you looking for - a doctor or what?’

'No someone who will carry on with the study of the Talmud. Learning...’

'You wouldn’t want your daughter to marry a physicist?’

Mrs Greenhouse shrugged. 'A physicist? I would say second-rate. A doctor, a lawyer, an accountant, I would say second-rate. Somebody else might say, "My son the doctor”. My son the doctor, very nice, but I would say, “My son the rabbi”; that’s important to me.’

Rabbi Pinter laughed. 'So a girl would look at a doctor and say he didn’t make it in learning!’

The phone rang, and Rabbi Pinter answered it. It was the London editor of Hamodia, 'the newspaper of Torah Jewry’, which is published in Israel, New York and Stamford Hill, and to which Rabbi Pinter acts as unpaid consultant. 'With respect,’ he said, 'you want me to talk to a tuppence ha’penny Israeli newspaper when I’m talking now to The Daily Telegraph?’ He gave me a broad wink, and hung up.

'People will tell you I’m wasted here,' he said with a laugh. 'I can think out of the box - and that skill I got through Talmud. I can think straight, I can think horizontally, and I can think with my head as well. Talmud develops a person morally, ethically and intellectually.’

Almost all of Rabbi Pinter’s students at Yesodey Hatorah would go on to study at a seminary, either in London, Manchester or Gateshead. None would go to university - 'because at present there isn’t the environment for Haredi girls to do that’ - although some might do Open University courses while continuing to live at home. His daughter, he said, had gained a BA, 'without stepping into university’, and now teaches history at the school. Midwifery is a particularly popular option - and in Stamford Hill there is no shortage of opportunities to practise it.

But for women, the primary expectation is to marry, create a home and raise their children in the faith. 'Our experience,’ Rabbi Pinter said, 'is that the better educated girls turn out to be the most successful mothers. For us, that’s the most important role a woman plays.’

Because of the size of families, and the emphasis put on continued religious studies, poverty is a real problem in the community. A 2006 study of the Stamford Hill community, Between Torah Learning and Wage Earning, published by the Floersheimer Institute for Policy Studies in Jerusalem, estimated that more than half the households below retirement age were receiving a means tested benefit of some sort, 62 per cent of families in the study were receiving child benefits, and 70 per cent receiving housing benefits. Of those, 70 per cent reported finding it 'difficult’ or 'very difficult’ to fund the gap between housing benefits and real rent levels.

Agudas Israel Community Services is an independent body that gives advice to the Stamford Hill Haredi on welfare, employment and immigration issues. An affiliated housing association has more than 500 residential units in Stamford Hill, neighbouring Haringey and Manchester.

Housing, Michael Posen the director of the advisory service told me, was a major concern among many Haredi in Stamford Hill. Of the 3,500 families in the community, more than 2,000 live in private rented accommodation; housing is scarce and and there are high levels of over-crowding.

The proposed government changes to cap housing benefit at £400 for properties of four bedrooms or more threaten to bring further hardship, Posen said. He estimates that more than 100 families in the community will be affected.

'As a community we’re very much aware of the financial state of the country and agree that something has to be done. But a lot of what the government has proposed will affect larger families disproportionately to smaller families. Vastly disproportionately.’

People in the community had a mixed view of drawing benefits, Posen went on. 'I have had people come in here who on principle will not claim anything at all, including child benefit. There are some people who will take child benefit, but they won’t take housing benefit because they don’t want to rely on a government hand-out. But in terms of stigma... not generally because there are so many people have to rely on it. It’s not a social security benefit; it’s not income support; it’s not signing on. Jobseeker's Allowance, yes there would be embarrassment.’

I wondered, would worsening financial straits perhaps encourage people to have smaller families? 'No one’s going to say that,' Posen said. 'There are people who for medical or emotional reasons might be encouraged to use contraception; but for financial reasons... that would be against our whole ethos. For that we can rely that we will be looked after by God.’

'There is a love of children, which is very central to the community,’ Rabbi Pinter told me. 'To us it’s the reason why we’re here. It’s all about continuity.’

It might be argued, I said, that in this day and age one should be thinking about limiting numbers. He shot me a look. 'It’s like saying, you’ve got this wonderful school building - what do you need all these bloody kids here for?’

An authority in Jewish law offered another view. In some parts of the community people’s worth was measured 'by how many children they have and how long their beard is’, he said with a sigh. 'Some people will express frustration that there are people having large numbers of children. But that’s balanced against the fact that in the Jewish world there’s a very strong premium on having children. We’re good at once in a while being completely wiped out. It’s one of our historical specialities.’

The important thing to remember about the Haredi community, Posen told me, was how tightly knit and and mutually supportive it was. There was a complex web of organisations and voluntary groups giving support on everything from care of the elderly to providing bridal gowns for those unable to afford them.

It was a place where people rich and poor live cheek by jowl, where one is expected to help the other, and where people dug deep. Rabbi Pinter had described it to me as 'a model of The Big Society in practice’.

Posen pointed out of the window of his office. Next door was a block of Agudas Israel housing association flats, where virtually everybody, he said, lived on benefit support. Beside that was a large house - 'you can just see the swimming pool’ - owned by a man who had made his fortune in property and the diamond business. 'But he would never think of moving out.’

According to a 2002 survey of the Stamford Hill Haredi, 'Torah, Worship and Acts of Loving Kindness’, more than half of the community is actively involved in some form of voluntary work - compared with around seven per cent for London overall - with some people working for as many as eight different organisations.

(The same survey threw up an enlightening statistic on the depth of religious observance: of the men questioned, 81 per cent had attended a religious talk in the previous two months, compared with two per cent who had attended a concert of classical music, and only one per cent who had watched a sports event or visited a cinema. 28 per cent, however, had visited a shopping centre.)

Crime within the community is rare; there are no gangs, no knifings; violent crime is virtually non-existent, domestic abuse rare - although fear of being the victim of crime or of anti-Semitic abuse is high. The Shomrim comprise some 20 volunteers, manned with two-way radios, who provide a sort of instant-response citizen force which Isaac Kornbluh told me could be on the scene of a bag-snatching or an assault within one or two minutes, tailing the offender until the police arrived to make an arrest.

The community has its own ambulance service, Hapzolah, with trained paramedics, and two weekly newspapers.

The Jewish Tribune, which is published from Stamford Hill, concentrates more on parochial issues. Hamodia ('the informer’) carries world news from its New York and Israel offices, and general stories deemed to be of interest to British Orthodox Jewry - a report on anti-Semitism being taught Islamic schools, Government cuts on migrant workers - as well as local news.

The tone is avowedly religious, everything refracted through the Torah way of life. There is no coverage of the arts, sport or books. Secular culture simply does not exist. The photographs are almost exclusively of distinguished rabbis, beaming out from behind capacious beards, behatted men gathering for some speech or celebration. It takes a moment for the outsider to put his finger on what is missing. There are no pictures of women. It is forbidden.

'The intention is that a person who doesn’t have a television, use the internet or read a secular newspaper can buy Hamodia and read all the news you need,’ Vicki Belovski, a freelance writer who works as the paper’s community news editor, told me.

News coverage is necessarily selective. One of the biggest stories of last year, Wikileaks, was not reported at all. The paper does not cover anything to do with the internet, Vicki Belovski told me, and it would have been unthinkable to report that Julian Asssange had been accused of sexual assault. 'It’s a family newspaper. We’re very careful about anything like that. There shouldn’t be any news in the paper that, in theory, the most sheltered person couldn’t pick up and read with their children.’

Abiding by the Torah injunction of shmiras halashon - 'guarding the tongue’ - local news in the paper avoids anything that might offend or be controversial. Within the community there had been much discussion over the subject of kosher milk. Traditionally there was one supplier that had the stamp of approval from the Kedassia, the rabbinical authority that certifies products as kosher; now a second supplier is selling milk that is cheaper. Cut-throat commercial dealing, squabbling rabbis - it had all the elements of a page-one lead, but Hamodia had not touched the story.

When I discussed this with Rabbi Pinter he shrugged. 'The editor is a particularly nice person and he doesn’t want to upset anybody. Anything that would be critical of somebody in the community would be considered gossip. It’s not what the community expects.’

But supposing somebody was being dishonest, or some sort of abuse of power or position was occurring? Is it not the paper’s job to report that?

'The Rabbinate have to deal with it. It’s not the newspaper’s job. People find out about things,’ Rabbi Pinter went on. 'But let them find out from somewhere else.’

A Haredi man put another spin on this. Stamford Hill was a place where many of the more grievous social problems that afflict the wider world were almost totally unknown. But it was also a community that tended to treat the things it didn’t want to see - the use of drugs, domestic difficulties, broken marriages - as if they didn’t exist at all.

In recent years, child abuse has become a subject of much discussion in the American Hasidic community, with revelations of abuse by rabbis that echo the scandals that swept through the Catholic community.

In 2008 the Jewish Chronicle reported that a rabbi from New York, Nochum Rosenberg, who runs a hotline for children to report abuse, was forced to flee from a Stamford Hill synagogue where he was listening to a lecture after being recognised and chased by 200 Haredi men. Reports of the incident posted on Jewish websites in America prompted hundreds of comments, the majority attacking Rabbi Rosenberg’s campaign.

On Dunsmure Road there is a parade of kosher shops - a baker, a butcher, a supermarket. A railway line runs near by and beside it - with exquisite irony - a street named West Bank. I had it in mind to visit a synagogue, and in a shop selling Judaica, music CDs and greetings cards, I bought a yarmulke, to the evident amusement of the sales assistant. Garishly painted portraits of great rebbes, living and dead, hung on the walls - home decoration.

In the darkening afternoon, the schools were letting out, and the streets were thronged with mothers and children, earnest Torah scholars hurrying home for tea and family duties, the gutteral cadences of Yiddish carrying on the air. London had never seemed more like a foreign city.

At the bottom of Egerton Road stands Stamford Hill’s largest and most impressive place of worship, the New Synagogue - a handsome Edwardian replica of the 19th-century Great St Helen’s Synagogue in the City of London, long since demolished. The New Synagogue was originally of the United Synagogue affiliation, but became defunct some 25 years ago when that congregation dwindled and its last remaining members moved away. In recent years it has become the headquarters of the Bobov Hassidim (considered the most dandified of the sects, I was told, because of their custom of wearing their white knee socks pulled over their black trousers) who, with the help of an English Heritage grant, have restored the building to its original glory.

The door was locked. On an impulse, I crossed to a building on the other side of the road and pulled open the door. It was a yeshiva. A group of teenage boys milled in the hallway between lessons. They greeted my appearance with looks of shock and surprise. A stranger, and a goy at that! A boy stepped forward and I explained that I wished to look at the synagogue. He disappeared to consult with somebody, then returned with a key saying he would show me himself. He was 14, he said, 'but people say I look older’. His upper lip and cheeks bore the faint traces of a moustache and beard. At the door I reached in my pocket for my new yarmulke. 'They sold you that?’ The boy’s voice wavered between amusement and disbelief.

He stepped inside and gestured proudly towards the soaring marble pillars, the cupola’d ceiling. 'See how beautiful it is.’

Ranged in shelves along the back were bound copies of the Torah, the Talmud. The boy pulled out a volume and turned the pages - right to left in Hebrew - running his finger over the blocks of text, here the teaching, here the commentary on the teaching.

So do you want to be a rabbi, I asked.

'Yes. Maybe.’ He paused. 'So are you thinking of becoming a Jew?’

I was told that I should meet Joe Lobenstein. A bastion of the Haredi community, Lobenstein has lived in Stamford Hill since before the war, when he arrived in Britain as a refugee from Germany. He is vice-president of the Union of Orthodox Hebrew Congregations, and was a local councillor for 38 years (the Haredi of Stamford Hill are as dependable an ethnic voting bloc as the Tammany Hall Irish in 19th-century New York) and four times mayor of Hackney.

He is a succesful businessman, who runs a large electrical cable distributors. I met him at his warehouse in Leyton, a short drive from Stamford Hill. Lobenstein founded the business 61 years ago with his father, and now runs it with two of his sons. He has eight children. 'It’s part of our religion not to count grandchildren. But I can tell you I have enough to man a number of football teams.’ He paused. 'Actually I’ve lost count.’

The Haredi community, he said, was wary in its association with outsiders, he said - a legacy of history, perhaps. He remembered how when he first became a councillor in 1962 people thought he was mad.

'How can you, a Jewish boy, just come out of the clutches of Hitlerism, get into political life? It was very unusual for anybody to mix in this political environment. But I did.

'Naturally there are people who are more fearful than others. It’s a question of the individual. But we do business... I have customers of all persuasions. I get on with everybody. I wear my skullcap and I do what I have to do, and people have to take me as I am.’

Lobenstein is 83 but he still comes to work each day, after morning prayers, and studies the Torah each evening. 'The Torah is, or ought be, a lifestyle for every Jewish person. There are some people who don’t observe some of these laws.’ He shrugged. 'That’s a great pity. A person who lives by the Torah is a happy person, and a group of happy people are by definition a happy community.’

To preserve this happiness, he suggested, it was necessary to keep the outside world at arm’s length. 'For example, you will not find an Orthodox Jewish home with a television. It teaches people how to steal; it shows people how to kill. So why should I expose my children and my grandchildren to this lifestyle which I regard, and my religion regards, as absolutely abhorrent.’

The immorality of today... He shook his head. For much the same reason he would strongly discourage any of his grandchildren from going to university. 'University life today is so infested with revolutionary ideas and secular ideas that I would not like my grandchildren to be exposed to that sort of influence.

'It doesn’t say in the Bible that you mustn’t send children to a non-Jewish school; it’s just that when you look around and you see what’s going on here... it’s the promotion of a lifestyle that I regard, and the Jewish religion regards, as abhorrent.’

We talked about the dilemma facing Stamford Hill - the rapid growth of population, the rising rents, the overcrowding. For some years there had been a running battle with the local Hackney Council, he said, which has placed stringent limits on roof extensions. 'In my years as a councillor I have met hundreds and hundreds of residents of this borough who have complained about the state of the road, the cleanliness, all sorts of things. Not a single person has complained to me that there are too many roof extensions. Some people in our community feel that some people in power don’t want to oblige us...’ His silence implied a multitude of agendas. 'It makes people feel uncomfortable,’ he said at last.

I asked Lobenstein if he might arrange for me to visit a kollel. 'People don’t much like the press,’ he said. 'I’m not sure it would be appreciated.

At length I found my way to nearby Golders Green, a more affluent area than Stamford Hill and home to a large Orthodox community and a small Hasidic one.

Sabbath begins at sunset on a Friday. The synagogue was the converted ground floor of a house on a quiet residential side-street. The congregation comprised some 50 men, all black-hatted, some in frock-coats, some in black suits, some in bekishes, the long silk gown traditionally worn on Sabbath and special occasions. Several wore the flamboyant fur Sabbath hat, or shtreimel.

Sabbath is seen as a time of ecstasy, to enjoy the world. The keening sound of the traditional Sabbath song, Lekhah Dodi ('come my beloved’), which likens the Sabbath to a bride, filled the small room; the chanting of prayers sounded like water running over stones.

A rabbi had invited me to join him, his wife and seven children and some friends for the Shabbos meal. The Sabbath law prohibiting anything that 'creates work’ encompasses a range of activities from driving or taking a bus, to switching on an electric light. The lights in the house had been set on an automatic timer, and the switch on the downstairs toilet bore a sign, for my benefit perhaps, 'Do not turn off’.

The food, the wine - a kosher cabernet from Galilee - and the conversation flowed. It was both an intoxicatingly joyous family occasion and a profoundly religious one, the rabbi an extrovert combination of paterfamilias and teacher. Over gefilte fish, he engaged his 14-year-old son in a lively debate on the Talmudic concept of yiush ('despair’) - at what point the finder of a lost object is permitted to regard it as his own. The roast chicken was followed by a learned discourse - 'tonight’s Torah portion’ - on the subject of Moses’s stammer, the rabbi cradling his baby son on his lap as he talked. And the songs! One after another of traditional zemirot , or table hymns - this one from the Gerer, this one from the Bobover - songs of deep devotion and high sentiment. A woman at the table brushed a tear from her eye. The bride of Sabbath had arrived. The baby slept peacefully in the rabbi’s arms.

It would be true to say that many of the 613 Mitzvot that form the basis of Haredi life have little application to life in 21st-century Stamford Hill. Few would be minded to destroy fruit trees during a siege, for example, or to contemplate dwelling permanently in Egypt.

But the diktats relating to diet, worship, family and commerce have been refined over centuries of rabbinical commentary and debate into a labyrinthine body of law and custom that governs every aspect of daily life - reinforced by what are known as 'gezerah’, or the precautionary measure - a fence, as it were, to guard against any possible transgression.

'For instance,’ Michael Posen told me, 'the rabbis have said that you should not be in a locked room with a member of the opposite sex, even though nothing is going on. But it’s to avoid you coming into an opportunity of doing something that’s incorrect.’

By this same principle, that it is better to be safe than sorry, it is deemed advisable not to go into a newsagent - who knows what you might see on the top shelf? - and to use a special 'kosher’ phone, on which text-messaging is disabled. 'You can open a text and it can start a process,’ Posen explained. 'It can lead to other things...’ He did not specify what.

Strolling around Stamford Hill, it occurred to me that to be Haredi was to walk with one’s eyes half-closed to the enticements and corruptions of the world around you, the advertisements on hoardings, and the side of buses - what exactly is Twilight? - the blare of pop music from a shop doorway. How to preserve the values of the community - and by definition its separateness - in the face of the wider society around it... It was the question that puzzled me wherever I went.

I asked Rabbi Pinter, how aware would his pupils be of the currents of popular culture eddying through society? Would The X Factor figure in his pupil’s conversation on a Monday morning?

'They wouldn’t be aware of what The X Factor is.’ He paused. 'I’m not sure I’m aware of what The X Factor is. But I think they’d say, what are they all going crazy about? One of the reasons why our children are so focused on education and why they are doing so well is because they don’t have those distractions. They have a real appreciation for a modest way of life. I think they would say, why are we idolising David Beckham and - what is she called? The Posh person? What are we getting out of this?’

But living by a code of such tightly imposed rules and guidelines, what cost was exacted in individual freedoms?

Rabbi Pinter thought about this. 'Everybody nowadays talks about “my rights”. What that usually means is “I have the right to do what I want and you have to take responsibility for that, because I have no responsibilities at all”. We don’t believe in that. There are limitations to individualism, and I will willingly give up that individualism because I believe I’m part of a society that is more important than me as an individual.’

Supposing, I asked, somebody had come to the realisation that they were gay? Rabbi Pinter sucked in his cheeks. 'They would be offered support and advice. We wouldn’t make you marry - well some might, but I wouldn’t. But it’s not a lifestyle that you can carry out. So a gay person would limit their behaviour or leave the community.’ He paused. 'I think most would knuckle down.’

There were, of course, young Haredi who rebelled against the burden of conformity - of course there were. But they were few. When I asked about this the word most often used was 'dysfunctional’.

'An outsider may say that whether you study the Torah for an hour each evening or switch on Coronation Street is simply a cultural variation,' one man told me. 'But that’s not how it’s presented to us - and, more important, it’s not how it feels to us. Sitting around the Sabbath table or figuring out a Talmudic conundrum with a child is not just like having Sunday roast together as a family. To us, it is part of what we see as our sanctification, something that is uniquely ours and which we will fight tooth and nail to hold on to. The child who won’t attend the Sabbath meal will have his or her parents concerned not simply that he or she is antisocial or may be depressed but that it is the beginning of drifting away, and that they’re losing the child. That is not only in defiance of the child’s parents and family but of our whole way of life.’

For a boy and girl to go out together on a date, to go to pop concert, to dissent from the code of dress - such things, it was suggested, would be almost unthinkable. 'For a child in the Haredi community to buy a pair of jeans,’ Michael Posen told me, 'there would have to be something really troubling him.’

But if there is a fence, it is a fence that has holes. At the London Jewish Film Festival last year there was a screening of the American film, Romeo and Juliet In Yiddish, which tells the story of a young masters student who seeks the help of two Hasidic drop-outs from Brooklyn to translate Shakespeare’s play into Yiddish. To the astonishment of many in the audience, a large contingent of young Haredi from Stamford Hill turned up to see the film. The comedian David Schneider, who was chairing the evening - and who himself studied Yiddish at Oxford - made a point of greeting the group, 'Hello, this is a cinema, this is electricity...’. eliciting a huge cheer from the Haredi themselves.

But it is the internet that constitutes perhaps the greatest trojan horse for outside influences to enter the community. Computers are tolerated, but ostensibly only for business. In the Jewish Tribune, I read a column by Yitzchak Reuven Rubin, a venerable Manchester rabbi, warning of how the internet 'slips into every nook and cranny with a subtle power that can overwhelm the sturdiest of souls.’ Members of 'the Torah community', he warned, 'should remain ever vigilant'.

A desperate - and ultimately futile - caution. 'Anyone with half a brain has realised that the attempt to control it has failed and could never have succeeded,’ one Haredi man told me.

Despite rabbinical disapproval, he went on, most people have internet access, if not at home then at local libraries. How else to book a flight to America or Israel for a sister’s wedding? He suggested I Google Shloime Gertner, whose sentimental religious and wedding songs have made him a star in the London Haredi community (I had heard of Shloime - 'The Hasidic Robbie Williams!’ as one person put it). There was no shortage of YouTube videos, and Shloime had more than 1,000 Facebook friends.

Surfing the web, I even came across a couple of Haredi bloggers - a particularly challenging pastime in a community where to openly express a controversial or contrarian opinion is to bring opprobrium on your head, and where to do it in a medium that is already disapproved of is to be twice damned. The liveliest blog goes under the name of If You Tickle Us (Boy Will We Laugh). It was here that I read an irreverent account of the kosher milk controversy ('Stamford Hill is in a lather or, given the subject matter, perhaps that should be a latte’).

I contacted If You Tickle Us and asked if we might talk. He replied: 'I’d love to talk and even meet, but....’ He would, however, send some thoughts. I received an email a few days later. I felt I was reading samizdat. He wrote at length about living in a community which had, he said, to some extent achieved its aim of 'trumping modern life’, which cherished its traditions, its religious observances its strong family values, but which also 'flatly ignores or denies the many problems inherent in its way of life'.

'Since the Torah is the truth,’ he wrote, 'our path must be of primrose, and since our path is indeed of primrose it proves the supremacy of a Torah way of life. Hence it follows that to criticise some of the fundamentals which underlie our way of life is to challenge the Torah itself. Problems are thus ignored if not denied altogether, criticism is silenced because an alternative is unfathomable, creativity and originality is suspect if not heretical, and change when necessary is either smuggled in unnoticed or presented as a legitimate variant of the status quo.’

He wrote of the limitations of an education system in which 'scholarliness is often a euphemism for ignorant piety’, and where the emphasis on religious knowledge left most students ill-equipped to face the outside world.

'If dissociating yourself from the broader society extends to cutting yourself off from basic knowledge like maths, geography, history and even simple skills like writing which in turn feed into an inability to earn a living, respectfully and honestly then the question must be: what is gained by such insularity?’

'Very few,’ he went on, 'will confront the fundamental issues, or that our way of life is not suited for everyone. So many spend a frustrated life of unfulfilled potential. This generates envy, extremism, dependency and an overall despondency which is seldom discussed.’

But it was also, he wrote, a community of immense warmth and self-reliance, with a level of philanthropy that would 'leave you gaping’; a community that instilled a powerful sense of identity, 'a pride in who you are, your culture and your history.’ It is, he concluded, 'a way of life that I love a great deal but which I am also frustrated with in almost equal measure. But ultimately it is my own and there is a Talmudic expression which encapsulates my feelings. “A person prefers a single measure of his own to nine measures from someone else”.’

A few days later I received another email. That morning he had attended the 8am service at synagogue, and there was a story he wished to share.

'I had walked in late and donned my prayer shawl and tefilin in an anteroom. As I was wrapping myself in my prayer shawl I accidentally jabbed the guy standing near me. This is a guy who though I see him regularly in the morning I have never exchanged a word with. While unwrapping myself I said “sorry” to him. He bent forward and said with a smile, “We Hasidim don’t say 'sorry’, we serve a jab in return”.’

The more time I spent in Stamford Hill, the more I thought about the contradiction of a community whose values depend on keeping the world at bay. It is a community that must, inevitably change. Economic hardship, rising rents, a chronic shortage of accommodation, limited employment opportunities, all mean that the Haredi must increasingly look outwards. Stamford Hill can no longer support its burgeoning Haredi population, but where are they to go?

For years, there has been talk of a diaspora, of perhaps 100 or 150 families, enough to build the foundations of a new community, with its own synagogues, schools and kosher shops, relocating elsewhere. In the early 1980s there was talk of taking over a former psychiatric hospital in St Albans that was being converted into residential accommodation. But nobody wanted to move to St Albans.

More recently, there were discussions with the then mayor of London Ken Livingstone about transplanting a Haredi community within the Thames Gateway, of pioneering in Milton Keynes, or close to Stansted Airport. 'It’s always been my dream,’ Rabbi Pinter told me. 'The problem is it probably needs some government involvement in helping us to do that. But if we can build an infrastructure somewhere out there, why not?’

Joe Lobenstein was doubtful.

'On paper this is fine, but it won’t work.’ He shrugged. 'When I got married - 58 years ago - there was already talk of moving to Ilford. It’s all talk. We are so wedded to Stamford Hill. We’ve got our synagogues here, our schools, our clubs - there’s no question of moving.’

He thought for a moment.

'I’ll tell you the truth - we are always concerned. We always have problems. But always bear in mind we have a pattern in the past.’ He told me a story to illustrate this. When he took his driving test, 'about 65 years ago’, the examiner had asked, 'What do you think is the most important part of the car?'

'I wasn’t quite sure what he was driving at - was it the brakes, the steering wheel? And then it occurred to me, I think it’s the wing mirrors. And I’ll tell you for why - you cannot drive forwards without also looking backwards. We look at how our parents grew up, our grandparents grew up. The times have changed, the environment has changed, but our basic way of life must continue from generation to generation.’